The Top Quark Partner T In The High-energy Collider May Be The Physical Signal

Content:The standard model (SM) is one of the greatest achievements in particle physics, and it tested by the high energy experimental data. However, SM still suffers some theoretical problems of too many free parameters, triviality, and unnaturalness, etc. Therefore, SM can only be an effective theory below some high energy scale. There may be new physics beyond the SM. In 2006, the left-right twin Higgs (LRTH) model was presented, it is a good method to implementing the twin Higgs mechanism and solving the little hierarchy problem. In the LRTH model, beyond the SM predict the existence of many new particles, the top partner as heavy as 1 TeV is one of these new particles. In this paper, we study the signatures of the top partner in the high energy colliders, which play an important role in investigating the LRTH model. Firstly, in the LRTH model, we study that the production of top partner associated with the top quark in the future high-energy linear e+e-collider (ILC) through the s-channel Z change and ZH change. According our conclusions, we have to say that it is difficult to discriminate the top partner for the ILC experiment. In the LRTH model, we further study that the single production of the top partner via the process epâ†'eb+Xâ†'veT+X at the lianc-ring type ep collider (THERA). Our numerical results show that, for 100 GeV≤M≤300 GeV and 500 GeV≤f≤1000 GeV, the value ofσ2LR is in the range of 72.7 fb～0.1 fb, so it is possible to detect the top partner via the process epâ†'eb+Xâ†'veT+X at the THERA. Thirdly, at the large hadron collider (LHC), we study that the production of the top partner associated via the subprocesses ggâ†'tT+tT and qqâ†'tT+tT(q=ux,c,d,s and b) in the LRTH model. From the results we can see that, the yearly integrated luminosityï¿¡int=100 fb-1 for the LHC with the center-of-mass energy (?)=14 TeV, and for 100 GeV≤M≤300 GeV and 500 GeV≤f≤1500 GeV, the value of the total hadronic cross section is in the range of 177.6 fb～0.013 fb. Thus, there will be several up to ten thousands of the tT+tT events to be generated per year, so it is very possible to detect the top partner. Except the LRTH model, most of all the new physics models predict the existence of the top partner, the littlest Higgs model with T-parity (LHT model) is one of the important new physics models. The LHT model predicts the existence of the top partner T+ which is T-even, and the top partner T_ which is T-odd. For distinguishing the top partner in the high energy colliders, we calculate the production of the top partner T+ in the LHT model. Compare the results of the LRTH model to the LHT model, we can see that, in the most of the parameter space, the cross section for the production of the top partner in the LRTH model is larger than in the LHT model. Therefore, the top partner will be detected and distinguished for the high energy collider experiments.